Impact absorption structure for vehicles

ABSTRACT

The crush can  4  is provided therein with the ribs  46  and  47  extending in the vehicle front and rear direction. The bumper beam  6  is provided therein with the ribs  66  and  67  extending in the vehicle front and rear direction. The rib  46  of the crush can  4  and the rib  66  of the bumper beam  6  are disposed at approximately the same height, and the rib  47  of the crush can  4  and the rib  67  of the bumper beam  6  are disposed at approximately the same height.

TECHNICAL FIELD

The present disclosure relates to an impact absorption structureprovided in a vehicle, and more particularly, belongs to a technicalfield of a structure of absorbing energy by crushing deformation in avehicle front and rear direction when an impact is applied from thevehicle front and rear direction.

BACKGROUND ART

In general, on the front part of an automobile, a front side frame isdisposed on each of right and left sides of the front part to extend ina front and rear direction of the automobile. Crush cans are attached tothe front end portions of these front side frames so as to absorb energyby crushing and deforming in the front and rear direction when an impactload is applied from the front of the automobile. Moreover, a bumperbeam is fixed to the front end portions of the right and left crush cansso as to extend in a width direction of the automobile (for example, seePATENT DOCUMENTS 1 and 2).

The crush can of PATENT DOCUMENT 1 is provided therein with ribsextending in the front and rear direction. Furthermore, the bumper beamof PATENT DOCUMENT 2 has a front wall part and a rear wall partextending in a vertical direction and ribs extending from a rear surfaceof the front wall part to a front surface of the rear wall part andextending in a right and left direction.

CITATION LIST Patent Document

PATENT DOCUMENT 1: Japanese Unexamined Patent Publication No.2003-127896

PATENT DOCUMENT 2: Japanese Unexamined Patent Publication No.2013-203304

SUMMARY OF THE INVENTION Technical Problem

As disclosed in PATENT DOCUMENT 1, the ribs provided in the crush canscan increase support stiffness, and an energy absorption amount, of thebumper beam.

Here, assuming a light collision in which a vehicle collides with anobstacle at a vehicle speed, for example, 15 km/h or less, the impactload is applied to the bumper beam and then is applied to the crushcans. In such a case, the impact load applied to the bumper beam couldeasily be transmitted to the crush cans at an initial stage by the ribsprovided to the bumper beam as disclosed in PATENT DOCUMENT 2. However,if the ribs extending in the front and rear direction as disclosed inPATENT DOCUMENT 1 are provided to the crush cans when a collision loadat the time of a light collision is applied to the bumper beam and istransmitted to the crush cans via the ribs of the bumper beam, the loadis transmitted only to a part of the front end portions of the ribs ofthe crush cans, such that only a part of the ribs is deformed and thusthe load is not transmitted, and the other parts may serve as props tointerfere the crushing and deforming of the crush cans, causingdeformation of the front side frames in some cases.

That is, even though an impact load is applied to the crush cans at theinitial stage of the light collision, the crush cans might not becrushed and deformed as desired due to the influence of the ribs of thecrush cans.

The present invention has been made to solve the aforementionedproblems, and an object of the present invention is to improve energyabsorption performance of a crush can having ribs by allowing the crushcan to be reliably crushed due to an impact load at the time of a lightcollision, thereby reducing deformation of a front side frame.

Solution to the Problem

In order to achieve the aforementioned object, in the present invention,when viewed from a front and rear direction, ribs of a crush can andribs of a bumper beam are disposed to overlap each other.

The first invention is directed to an impact absorption structure for avehicle in which right and left crush cans are respectively attached tovehicle front end portions of front side frames disposed on both rightand left sides of the vehicle and extending in a vehicle front and reardirection, and a bumper beam is attached to vehicle front end portionsof the right and left crush cans to extend in a vehicle width direction,wherein each of the crush cans is formed in a cylindrical shapeextending in the vehicle front and rear direction and is providedtherein with a rib extending in the vehicle front and rear directioncontinuously to an inner surface of the crush can, the bumper beam isformed in a cylindrical shape extending in a vehicle width direction andis provided therein with a rib extending in the vehicle front and reardirection continuously to an inner surface of the bumper beam, and therib of the crush can and the rib of the bumper beam are disposed atapproximately a same height.

According to such a configuration, since the ribs are provided insidethe crush can, support stiffness of the bumper beam and an energyabsorption amount of the crush can increase. On the other hand, at thetime of a light collision, an impact load applied to the bumper beam isapplied to the crush can. In such a case, when viewed from the vehiclefront and rear direction, the ribs of the bumper beam and the ribs ofthe crush can are positioned to overlap each other and the ribs of thebumper beam and the crush can extend in the front and rear directionapproximately coinciding with the input direction of the impact load.Hence, the impact load is transmitted from the ribs of the bumper beamto the ribs of the crush can. In this way, since the impact load at thetime of the light collision is approximately uniformly applied to theentire front end portion of the ribs of the crush can via the ribs ofthe bumper beam, the ribs of the crush can are deformed such that theribs can be prevented from serving as props, so that the crush can isreliably crushed and deformed by the impact load at the time of thelight collision.

In the second invention, the crush can is provided therein with a firstrib and a second rib extending in the vehicle front and rear directionand spaced apart from each other in a vertical direction, the bumperbeam is provided therein with a first rib and a second rib extending inthe vehicle front and rear direction and spaced apart from each other inthe vertical direction, and the first rib of the crush can and the firstrib of the bumper beam are disposed at approximately the same height,and the second rib of the crush can and the second rib of the bumperbeam are disposed at approximately the same height.

According to such a configuration, the impact load is transmitted fromthe first rib and the second rib of the bumper beam to the first rib andthe second rib of the crush can. In this way, when the crush can isprovided with a plurality of ribs, each rib can be prevented fromserving as a prop.

In the third invention, the crush can includes an upper wall part and alower wall part extending in the vehicle front and rear direction, thebumper beam includes an upper plate part and a lower plate partextending in the vehicle front and rear direction, and the upper wallpart of the crush can and the upper plate part of the bumper beam aredisposed at approximately the same height, and the lower wall part ofthe crush can and the lower plate part of the bumper beam are disposedat approximately the same height.

According to such a configuration, the impact load is transmitted fromthe upper plate part and the lower plate part of the bumper beam to theupper wall part and the lower wall part of the crush can. In this way,at the initial stage in which the impact load at the time of the lightcollision is applied, the upper wall part and the lower wall part of thecrush can are deformed, so that the upper wall part and the lower wallpart can be prevented from serving as props.

In the fourth invention, the rib of the crush can is a horizontal ribextending in the vehicle width direction, the crush can is providedtherein with a vertical rib extending from the horizontal rib to theupper wall part or the lower wall part of the crush can and extending inthe vehicle front and rear direction, the bumper beam includes a rearplate part located at a vehicle rear side, when viewed from the vehiclefront and rear direction, the vertical rib of the crush can and the rearplate part of the bumper beam are disposed to overlap each other, and athickness of the vertical rib of the crush can is set thinner than athickness of the rear plate part of the bumper beam.

According to such a configuration, the vertical rib is provided insidethe crush can, so that support stiffness of the bumper beam is furtherincreased. Furthermore, when the impact load applied to the bumper beamat the time of the light collision is applied to the crush can, a partof the impact load is transmitted to the vertical rib of the crush canvia the rear plate part of the bumper beam. In such a case, thethickness of the vertical rib is thinner than that of the rear platepart of the bumper beam, so that the vertical rib can be deformed by therear plate part of the bumper beam.

Advantages of the Invention

According to the first invention, the ribs of the crush can and the ribsof the bumper beam are disposed at approximately the same heights, sothat it is possible to reliably crush the crush can by the impact loadat the time of the light collision. In this way, it is possible toimprove energy absorption performance of the crush can, so that it ispossible to suppress the deformation of the front side frame.

According to the second invention, the first rib of the crush can andthe first rib of the bumper beam are disposed at approximately the sameheight and the second rib of the crush can and the second rib of thebumper beam are disposed at approximately the same height, so that whenthe crush can is provided with a plurality of ribs, each rib can beprevented from serving as a prop.

According to the third invention, the upper wall part of the crush canand the upper plate part of the bumper beam are disposed atapproximately the same height and the lower wall part of the crush canand the lower plate part of the bumper beam are disposed atapproximately the same height, so that it is possible to prevent theupper wall part and the lower wall part of the crush can from serving asprops.

According to the fourth invention, when viewed from the vehicle frontand rear direction, the vertical rib of the crush can and the rear platepart of the bumper beam are disposed to overlap each other and thethickness of the vertical rib of the crush can is thinner than that ofthe rear plate part of the bumper beam, so that it is possible to deformthe vertical rib with the rear plate part of the bumper beam by theimpact load at the time of the light collision. In this way, it ispossible to prevent the vertical rib from serving as a prop.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view when an impact absorption structure for avehicle according to an embodiment of the present invention is viewedfrom the upper left.

FIG. 2 is a plan view illustrating a front part of the impact absorptionstructure for the vehicle.

FIG. 3 is a cross-section taken along line in FIG. 1.

FIG. 4 is a cross-section taken along line IV-IV in FIG. 1.

FIG. 5 is a cross-section taken along line V-V in FIG. 1.

FIG. 6 is a perspective view when a left crush can is viewed from thelower right.

FIG. 7 is a perspective view when the left crush can is viewed from theupper left.

FIG. 8 is a plan view of the left crush can.

FIG. 9 is a right side view of the left crush can.

FIG. 10 is a cross-section taken along line X-X in FIG. 8.

FIG. 11 is a cross-section taken along line XI-XI in FIG. 1.

FIG. 12 is a view corresponding to FIG. 6 according to a modificationexample 1 of the embodiment.

FIG. 13 is a view corresponding to FIG. 7 according to the modificationexample 1 of the embodiment.

FIG. 14 is a view corresponding to FIG. 8 according to the modificationexample 1 of the embodiment.

FIG. 15 is a view corresponding to FIG. 9 according to the modificationexample 1 of the embodiment.

FIG. 16 is a view corresponding to FIG. 6 according to a modificationexample 2 of the embodiment.

FIG. 17 is a view corresponding to FIG. 7 according to the modificationexample 2 of the embodiment.

FIG. 18 is a view corresponding to FIG. 8 according to the modificationexample 2 of the embodiment.

FIG. 19 is a view corresponding to FIG. 9 according to the modificationexample 2 of the embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present invention will be described indetail with reference to the drawings. The following description of apreferred embodiment is merely exemplary and is not intended to limitthe present invention, applications thereof, or usages thereof.

FIG. 1 is a perspective view when an impact absorption structure 1 of avehicle according to an embodiment of the present invention is viewedfrom an obliquely upper left. The impact absorption structure 1 isprovided, for example, at the front part of a passenger vehicle, andincludes a left front side frame 2, a right front side frame 3, a leftcrush can 4, a right crush can 5, and a bumper beam 6 extending in avehicle width direction. The left crush can 4 and the right crush can 5are attached to the front end portions of the left front side frame 2and the right front side frame 3, respectively. The bumper beam 6 isattached to the front end portions of the left crush can 4 and the rightcrush can 5. In the embodiment, it is assumed that the front side of thevehicle is simply referred to as “front”, the rear side of the vehicleis simply referred to as “rear”, the left side of the vehicle is simplyreferred to as “left”, and the right side of the vehicle is simplyreferred to as “right”.

The left front side frame 2 and the right front side frame 3 aredisposed on the left side and right side of a vehicle body,respectively, and extend in a front and rear direction while beingseparated from each other in a right and left direction. Between theleft front side frame 2 and the right front side frame 3, an engine, atransmission and the like (not illustrated) are disposed. Furthermore,the vehicle is provided with a dash panel DP (its schematic shape isindicated by a virtual line) that divides an engine compartment E and apassenger compartment (not illustrated). The dash panel DP extendsapproximately vertically. The left front side frame 2 extends to thefront from the vicinity of the left side of the dash panel DP, and theright front side frame 3 extends to the front from the vicinity of theright side of the dash panel DP.

The front part of the vehicle is provided with a left suspension tower 7formed in a tower shape on a left side of the left front side frame 2and a right suspension tower 8 formed in a tower shape on a right sideof the right front side frame 3. The sides of the left suspension tower7 and the right suspension tower 8 are provided with reinforcements 7 aand 8 a, respectively.

Furthermore, the vehicle is provided with a front bumper, a fender, anengine hood, and the like, but they are not illustrated.

(Configuration of Front Side Frame)

Since the left front side frame 2 and the right front side frame 3 aresymmetrical in the right and left direction, the structure of the leftfront side frame 2 will be described in detail below. As illustrated inFIG. 3 to FIG. 5, the left front side frame 2 has an upper plate part 21and a lower plate part 22 extending in the right and left directionwhile being separated from each other in the vertical direction, a leftplate part 23 extending in the vertical direction to connect the leftend portions of the upper plate part 21 and the lower plate part 22 toeach other, and a right plate part 24 extending in the verticaldirection to connect the right end portions of the upper plate part 21and the lower plate part 22 to each other, and has an approximatelyrectangular sectional shape as a whole. The dimensions of the left platepart 23 and the right plate part 24 in the vertical direction are set tobe longer than those of the upper plate part 21 and the lower plate part22 in the right and left direction.

As illustrated in FIG. 3, the upper plate part 21 extends approximatelyhorizontally from the front end portion to the rear end portion of theleft front side frame 2. The lower plate part 22 extends from the frontend portion to the vicinity of the rear end portion of the left frontside frame 2 in approximately parallel to the upper plate part 21, butthe vicinity of the rear end portion of the lower plate part 22 iscurved and extends to the rear side from the vicinity of the rear endportion of the lower plate part 22 to the rear end portion while beinginclined downward. As illustrated in FIG. 4 and FIG. 5, the left platepart 23 constitutes an outer part of the left front side frame 2 in thevehicle width direction, and the right plate part 24 constitutes aninner part of the left front side frame 2 in the vehicle widthdirection.

The left plate part 23 is provided with an outer recessed linear portion23 a for reinforcement. The outer recessed liner portion 23 a is formedin the intermediate portion of the left plate part 23 in the verticaldirection, and recessed toward an inner side (right side) of the leftfront side frame 2 and extending in the front and rear direction. Theouter recessed linear portion 23 a is recessed toward the inner side ofthe left front side frame 2, so that it is possible to reinforce theleft front side frame 2 without narrowing a lateral space of the leftfront side frame 2.

The outer recessed linear portion 23 a is not formed at a front endportion of the left plate part 23, and extends continuously from a rearportion, other than the front end portion of the left plate part 23, toa rear end portion of the left plate part 23. The depth of the outerrecessed linear portion 23 a is set shallower toward a front end portionof the outer recessed linear portion 23 a and deeper toward a rear endportion of the outer recessed linear portion 23 a. The depth of theouter recessed linear portion 23 a is a dimension of the outer recessedlinear portion 23 a in the right and left direction. Furthermore, adimension of the outer recessed linear portion 23 a in the verticaldirection is set approximately constant from the front end portion tothe rear end portion of the outer recessed linear portion 23 a, and inthe embodiment, the dimension of the outer recessed linear portion 23 ain the vertical direction corresponds to about ⅓ of a dimension of theleft front side frame 2 in the vertical direction and is approximatelyequal to a separation dimension in the vertical direction of an upperhorizontal rib 46 and a lower horizontal rib 47 of the crush can 4 to bedescribed later.

Although illustrated only in FIG. 4 and FIG. 5, the outer recessedlinear portion 23 a includes an upper portion 23 b and a lower portion23 c projecting to the inner side of the left front side frame 2, and anintermediate plate portion 23 d vertically extending from a distal endportion (right end portion) of the upper portion 23 b in the projectingdirection to a distal end portion (right end portion) of the lowerportion 23 c in the projecting direction. A separation dimension betweenthe upper portion 23 b and the lower portion 23 c corresponds to thedimension of the outer recessed linear portion 23 a in the verticaldirection. The upper portion 23 b is inclined to be located lower towardthe right end portion. Furthermore, the lower portion 23 c is inclinedto be located upper toward the right end portion.

The right plate part 24 is provided with an inner recessed linearportion 24 a for reinforcement. The inner recessed liner portion 24 a isformed in the intermediate portion of the right plate part 24 in thevertical direction, and recessed toward an inner side (left side) of theleft front side frame 2 and extending in the front and rear direction.The inner recessed linear portion 24 a is not formed at a front endportion of the right plate part 24, and extends continuously from a rearportion, other than the front end portion of the right plate part 24, toa rear end portion of the right plate part 24. That is, since the innerrecessed linear portion 24 a and the outer recessed linear portion 23 aare not formed at the front end portion of the left front side frame 2,the front end portion of the left front side frame 2 has anapproximately rectangular cross-section that is long in the verticaldirection. In this way, the upper portion of the front end portion ofthe left front side frame 2 is provided with two ridge line portions 2 aand 2 b spaced apart from each other in the right and left direction,and the lower portion of the front end portion of the left front sideframe 2 is provided with two ridge line portions 2 c and 2 d spacedapart from each other in the right and left direction. The ridge lineportions 2 a to 2 d are continuous from the front end portion to therear end portion of the left front side frame 2. The portions where theridge line portions 2 a to 2 d are formed have a higher strength thanthat of a flat plate portion of the left front side frame 2.

The depth of the inner recessed linear portion 24 a is set shallowertoward a front end portion of the inner recessed linear portion 24 a anddeeper toward a rear end portion of the inner recessed linear portion 24a. Furthermore, a dimension of the inner recessed linear portion 24 a inthe vertical direction is set to be the same as the dimension of theouter recessed linear portion 23 a in the vertical direction.

Similar to the outer recessed linear portion 23 a, the inner recessedlinear portion 24 a includes an upper portion 24 b and a lower portion24 c projecting to the inner side of the left front side frame 2, and anintermediate plate portion 24 d extending from a distal end portion(left end portion) of the upper portion 24 b in the projecting directionto a distal end portion (left end portion) of the lower portion 24 c inthe projecting direction. The upper portion 24 b is inclined to belocated lower toward the left end portion. Furthermore, the lowerportion 24 c is inclined to be located upper toward the left endportion.

The left front side frame 2 includes an outer panel OP and an innerpanel IP joined together. The outer panel OP is disposed on an outerside in the vehicle width direction, and the inner panel IP is disposedon an inner side in the vehicle width direction. The outer panel OP andthe inner panel IP, for example, are obtained by press-molding a steelplate and the like. Joining flanges OP1 and OP2 are formed on an upperpart and a lower part of the outer panel OP, joining flanges IP1 and IP2are formed on an upper part and a lower part of the inner panel IP, thejoining flange OP1 and the joining flange IP1, for example, are joinedtogether by spot welding, and the joining flange OP2 and the joiningflange IP2, for example, are joined together by the spot welding. Ajoining position of the outer panel OP and the inner panel IP is inside(right side) from the center of the left front side frame 2 in thevehicle width direction.

As illustrated in FIG. 3, a frame-side set plate 25 is fixed to thefront end portion of the left front side frame 2 so as to extend in thevertical direction. The frame-side set plate 25 is formed to be largerthan the outer shape of the front end portion of the left front sideframe 2, and is a member for attaching the crush can 4. Similarly, aframe-side set plate 35 is fixed to the front end portion of the rightfront side frame 3.

(Configuration of Crush can)

Since the left crush can 4 and the right crush can 5 are symmetrical inthe right and left direction, the structure of the left crush can 4 willbe described in detail below. As illustrated in FIG. 6 to FIG. 9, theleft crush can 4 includes an extrusion molding member having an upperwall part 41 and a lower wall part 42 formed in a cylindrical shapeextending in the front and rear direction and extending in the right andleft direction while being separated from each other in the verticaldirection, a left wall part 43 extending in the vertical direction toconnect the left end portions of the upper wall part 41 and the lowerwall part 42 to each other, and a right wall part 44 extending in thevertical direction to connect the right end portions of the upper wallpart 41 and the lower wall part 42 to each other. The extrusion moldingmember, for example, is a member molded by extruding a material such asan aluminum alloy and a magnesium alloy from a cap (not illustrated).

The dimensions of the left wall part 43 and the right wall part 44 inthe vertical direction are set larger than those of the upper wall part41 and the lower wall part 42 in the right and left direction, and theleft crush can 4 has an approximately rectangular sectional shape thatis long in the vertical direction as a whole. The dimensions of theupper wall part 41 and the lower wall part 42 of the left crush can 4 inthe right and left direction are set to be approximately equal to thoseof the upper plate part 21 and the lower plate part 22 of the left frontside frame 2 in the right and left direction. Furthermore, thedimensions of the left wall part 43 and the right wall part 44 of theleft crush can 4 in the vertical direction are set approximately equalto those of the left plate part 23 and the right plate part 24 of theleft front side frame 2 in the vertical direction.

The upper portion of the front end portion of the left crush can 4 isprovided with two ridge line portions 4 a and 4 b spaced apart from eachother in the right and left direction. The lower portion of the frontend portion of the left crush can 4 is provided with two ridge lineportions 4 c and 4 d spaced apart from each other in the right and leftdirection. The ridge line portions 4 a to 4 d are continuous from thefront end portion to the rear end portion of the left crush can 4.

Furthermore, the rear edges of the upper wall part 41 and the lower wallpart 42 of the left crush can 4 extend in the right and left direction.The rear edges of the left wall part 43 and the right wall part 44 ofthe left crush can 4 extend in the vertical direction. In this way, arear end surface of the left crush can 4 is a surface extending in thevertical direction and the right and left direction, and a crushcan-side set plate 45 (illustrated only in FIG. 1 to FIG. 3) is fixed tothe rear end surface. The crush can-side set plate 45 and the frame-sideset plate 25, for example, are fastened by fastening members such asbolts 100 and nuts 101.

The outer shape of the front end portion of the left front side frame 2and the outer shape of the rear end portion of the left crush can 4approximately coincide with each other. In this way, when viewed fromthe vehicle front and rear direction, the ridge line portions 2 a to 2 dformed at four portions of the front end portion of the left front sideframe 2 and the ridge line portions 4 a to 4 d formed at four portionsof the rear end portion of the left crush can 4 overlap each other, andthe front end portions of the upper plate part 21, the lower plate part22, the left plate part 23, and the right plate part 24 of the leftfront side frame 2 and the rear end portions of the upper wall part 41,the lower wall part 42, the left wall part 43, and the right wall part44 of the left crush can 4 overlap each other.

As illustrated in FIG. 3, since the set plates 25 and 45 are interposedbetween the left front side frame 2 and the left crush can 4, the leftfront side frame 2 and the left crush can 4 do not contact with eachother, but when viewed from the vehicle front and rear direction, thefront end portions of the plate parts 21 to 24 of the left front sideframe 2 and the rear end portions of the wall parts 41 to 44 of the leftcrush can 4 are in a positional relation so as to overlap each other.Furthermore, when viewed from the vehicle front and rear direction, thefront end portions of the plate parts 21 to 24 of the left front sideframe 2 and the rear end portions of the wall parts 41 to 44 of the leftcrush can 4 do not have to completely overlap each other, and adeviation corresponding to a half of the plate thickness is permitted.

On the other hand, as illustrated in FIG. 7 and FIG. 8, the front edgesof the upper wall part 41 and the lower wall part 42 of the left crushcan 4 extend in the right and left direction while being inclined with apredetermined inclination angle with respect to the right and leftdirection so as to be located rearward toward the left side. In thisway, the front edge of the left wall part 43 of the left crush can 4 islocated behind the front edge of the right wall part 44. The front edgesof the upper wall part 41 and the lower wall part 42 are shaped toconform to a shape of the bumper beam 6 to be described later.Furthermore, the front edges of the upper wall part 41 and the lowerwall part 42 of the left crush can 4 may curve and extend so as to belocated rearward toward the left side. Furthermore, the front edges ofthe left wall part 43 and the right wall part 44 of the left crush can 4extend in the vertical direction.

As illustrated in FIG. 7 and FIG. 10, the left crush can 4 is providedtherein with an upper horizontal rib (a first rib) 46 and a lowerhorizontal rib (a second rib) 47 extending from the right wall part 44to the left wall part 43, and extending in the front and rear directioncontinuously to the inner surface of the left crush can 4. The upperhorizontal rib 46 and the lower horizontal rib 47 are spaced apart fromeach other in the vertical direction. Furthermore, the left crush can 4is provided therein with an upper vertical rib 48 and a lower verticalrib 49. The upper vertical rib 48 extends in the vertical direction fromthe upper wall part 41 to the upper horizontal rib 46, and in the frontand rear direction continuously to the inner surface of the left crushcan 4. The lower vertical rib 49 extends in the vertical direction fromthe lower wall part 42 to the lower horizontal rib 47, and in the frontand rear direction continuously to the inner surface of the left crushcan 4.

That is, the upper horizontal rib 46 extends in the right and leftdirection from a part, above the vertical center, of the right wall part44 to a part, above the vertical center, of the left wall part 43, andextends from the front end portion to the rear end portion of the leftcrush can 4 approximately in parallel to the upper wall part 41. Thelower horizontal rib 47 extends in the right and left direction from apart, below the vertical center, of the right wall part 44 to a part,below the vertical center, of the left wall part 43, and extends fromthe front end portion to the rear end portion of the left crush can 4approximately in parallel to the lower wall part 42. By the upperhorizontal rib 46 and the lower horizontal rib 47, the inside of theleft crush can 4 is divided into three spaces in the vertical direction,that is, an upper space R1, a center space R2, and a lower space R3. Inthe embodiment, the dimensions of the upper space R1, the center spaceR2, and the lower space R3 in the vertical direction are set to beapproximately equal to one another.

The heights of the upper horizontal rib 46 and the lower horizontal rib47 are set approximately equal to those of the outer recessed linearportion 23 a and the inner recessed linear portion 24 a of the leftfront side frame 2. Specifically, the height of the upper horizontal rib46 is set to approximately the same heights as the upper portion 23 bconstituting the outer recessed linear portion 23 a and the upperportion 24 b constituting the inner recessed linear portion 24 a. Theheight of the lower horizontal rib 47 is set to approximately the sameheights as the lower portion 23 c constituting the outer recessed linearportion 23 a and the lower portion 24 c constituting the inner recessedlinear portion 24 a.

The upper vertical rib 48 extends in the vertical direction from thecenter of the upper wall part 41 in the right and left direction to thecenter of the upper horizontal rib 46 in the right and left direction,and extends from the front end portion to the rear end portion of theleft crush can 4 approximately in parallel to both the right and leftwall parts 44 and 43. By the upper vertical rib 48, the upper space R1is divided into two spaces in the right and left direction. The lowervertical rib 49 extends in the vertical direction from the center of thelower wall part 42 in the right and left direction to the center of thelower horizontal rib 47 in the right and left direction, and extendsfrom the front end portion to the rear end portion of the left crush can4 approximately in parallel to both the right and left wall parts 44 and43. By the lower vertical rib 49, the lower space R3 is divided into twospaces in the right and left direction.

The upper wall part 41 and the lower wall part 42 have approximate thesame thickness, and the left wall part 43 and the right wall part 44also have approximate the same thickness. Moreover, the upper horizontalrib 46 and the lower horizontal rib 47 have approximate the samethickness, and the upper vertical rib 48 and the lower vertical rib 49also have approximate the same thickness.

The left crush can 4 is provided with an induction part 40 for inducingcrushing when a compressive load acts in the front and rear direction.The induction part 40 includes a bead formed to be recessed to the leftin a position separated rearward from the front end portion of the rightwall part 44 at the front portion of the right wall part 44, and extendsfrom an upper end portion to a lower end portion of the right wall part44. A horizontal cross-section of the induction part 40 is a shape ofsubstantially circular arc opened rightward. Since the induction part 40is a groove-like part, a part of right edges of the upper wall part 41and the lower wall part 42 is cut out, so that cutout portions 41 a and42 a are formed in the upper wall part 41 and the lower wall part 42.Similarly, a part of right edges of the upper horizontal rib 46 and thelower horizontal rib 47 is cut out, so that cutout portions 46 a and 47a are formed in the upper horizontal rib 46 and the lower horizontal rib47. On the other hand, the left wall part 43 of the left crush can 4 isprovided with no induction part. The induction part 40 may be omitted.

(Configuration of Bumper Beam)

The bumper beam 6 is formed in a cylindrical shape extending in thevehicle width direction. That is, the bumper beam 6 has an upper platepart 61 and a lower plate part 62 extending in the right and leftdirection while being separated from each other in the verticaldirection, a front plate part 63 extending in the vertical direction toconnect the front end portions of the upper plate part 61 and the lowerplate part 62 to each other, and a rear plate part 64 extending in thevertical direction to connect the rear end portions of the upper platepart 61 and the lower plate part 62 to each other, and has anapproximately rectangular sectional shape as a whole. The dimensions ofthe front plate part 63 and the rear plate part 64 in the verticaldirection are set larger than those of the upper plate part 61 and thelower plate part 62 in the right and left direction.

Similar to the crush cans 4 and 5, the bumper beam 6 can also be formedinto an extrusion molding member; however, the present disclosure is notlimited thereto and the bumper beam 6 may be configured with apress-molded plate material. The bumper beam 6 is formed to curve as awhole in the plan view and has a shape in which both sides of the bumperbeam 6 in the vehicle width direction are located closer to the rearside as getting closer to the outer sides in the vehicle widthdirection, that is, the bumper beam 6 has a shape in which the center inthe vehicle width direction is located at the frontmost position. Such ashape of the bumper beam 6 is decided from a relation of vehicle design.Furthermore, the bumper beam 6 may have an inclined shape in the planview such that it is located on the rear side toward the outer side inthe vehicle width direction.

The bumper beam 6 is provided therein with an upper horizontal rib (afirst rib) 66 and a lower horizontal rib (a second rib) 67 extendingfrom the front plate part 63 to the rear plate part 64, and extendingcontinuously to the inner surface of the bumper beam 6. The upperhorizontal rib 66 and the lower horizontal rib 67 are spaced apart fromeach other in the vertical direction. The upper horizontal rib 66extends in front and rear direction from a part above the verticalcenter, of the front plate part 63, to a part, above the verticalcenter, of rear plate part 64. The upper horizontal rib 66 extends fromthe left end portion to the right end portion of the bumper beam 6approximately in parallel to the upper plate part 61. The lowerhorizontal rib 67 extends in the front and rear direction from a partbelow the vertical center, of the front plate part 63, to a part, belowthe vertical center, of the rear plate part 64. The lower horizontal rib67 extends from the left end portion to the right end portion of thebumper beam 6 approximately in parallel to the lower plate part 62.

The upper horizontal rib 46 of the left crush can 4 and the upperhorizontal rib 66 of the bumper beam 6 are disposed at approximately thesame height, and the lower horizontal rib 47 of the left crush can 4 andthe lower horizontal rib 67 of the bumper beam 6 are disposed atapproximately the same height. Note that, the upper horizontal rib 46and of the left crush can 4 and the upper horizontal rib 66 of thebumper beam 6 do not have to be disposed at completely the same height,and the lower horizontal rib 47 of the left crush can 4 and the lowerhorizontal rib 67 of the bumper beam 6 do not have to be disposed atcompletely the same height, and a deviation corresponding to a half ofthe plate thickness is permitted.

Furthermore, the upper wall part 41 of the left crush can 4 and theupper plate part 61 of the bumper beam 6 are disposed at the sameheight, and the lower wall part 42 of the left crush can 4 and the lowerplate part 62 of the bumper beam 6 are disposed at the same height. Notethat, the upper wall part 41 of the left crush can 4 and the upper platepart 61 of the bumper beam 6 do not have to be disposed at completelythe same height, and the lower wall part 42 of the left crush can 4 andthe lower plate part 62 of the bumper beam 6 do not have to be disposedat completely the same height, and a deviation corresponding to a halfof the plate thickness is permitted.

Furthermore, when viewed from the vehicle front and rear direction, theupper vertical rib 48 and the lower vertical rib 49 of the left crushcan 4 and the rear plate part 64 of the bumper beam 6 are disposed tooverlap each other.

By the upper horizontal rib 66 and the lower horizontal rib 67 of thebumper beam 6, the inside of the bumper beam 6 is divided into threespaces in the vertical direction, that is, an upper space S1, a centerspace S2, and a lower space S3. In the embodiment, the dimensions of theupper space S1, the center space S2, and the lower space S3 in thevertical direction are set approximately equal to one another. Theheights of the upper horizontal rib 66 and the lower horizontal rib 67approximately coincide with those of the upper horizontal rib 46 and thelower horizontal rib 47 of the left crush can 4, respectively.

Furthermore, the thicknesses of the front plate part 63 and the rearplate part 64 are approximately equal to each other, and are set thickerthan those of the upper plate part 61, the lower plate part 62, theupper horizontal rib 66, and the lower horizontal rib 67. Thethicknesses of the upper plate part 61, the lower plate part 62, theupper horizontal rib 66, and the lower horizontal rib 67 areapproximately equal to one another. Furthermore, the thicknesses of theupper vertical rib 48 and the lower vertical rib 49 of the left crushcan 4 are set thinner than that of the rear plate part 64 of the bumperbeam 6.

Advantages of Embodiment

Next, the advantages of the impact absorption structure 1 of the vehicleconfigured as above will be described. A description will be providedfor a case where an impact load of a predetermined degree or less isapplied from the front such as when the vehicle collides head on at alow vehicle speed (for example, 15 km/h or less) (light collision). Theimpact load from the front is applied to the bumper beam 6 via a frontbumper and the like (not illustrated), and compressive force acts fromthe bumper beam 6 to the left crush can 4 and the right crush can 5.Depending on the collision situation, there are a case where thecompressive force acts only on the left crush can 4 and a case where thecompressive force acts only on the right crush can 5.

Since the left crush can 4 and the right crush can 5 are attached to theleft front side frame 2 and the right front side frame 3, they receivethe compressive force between the bumper beam 6 and the left front sideframe 2 and between the bumper beam 6 and the right front side frame 3,respectively. In such a case, the ridge line portions 2 a and 2 b areformed at the upper portion of the front end portion of the left frontside frame 2, the ridge line portions 2 c and 2 d are formed at thelower portion thereof, and two portions having a strength higher thanthat of a flat plate portion are present at the upper portion and thelower portion of the front end portion of the left front side frame 2,respectively, so that the strength of the upper portion and the lowerportion of the front end portion of the left front side frame 2 isincreased.

On the other hand, similar to the front end portion of the left frontside frame 2, since the ridge line portions 4 a to 4 d are formed at theupper portion and the lower portion of the left crush can 4, thestrength of the upper portion and the lower portion of the left crushcan 4 is increased. Moreover, the strength of the upper portion of theleft crush can 4 is further increased by the upper horizontal rib 46 andthe upper vertical rib 48, and the strength of the lower portion of theleft crush can 4 is also further increased by the lower horizontal rib47 and the lower vertical rib 49.

Furthermore, the front end portions of the plate parts 21 to 24 of theleft front side frame 2 and the rear end portions of the wall parts 41to 44 of the left crush can 4 overlap each other, thereby obtaining apositional relation in which a high-strength portion of the upperportion of the left front side frame 2 and a high-strength portion ofthe upper portion of the left crush can 4 correspond to each other and apositional relation in which a high-strength portion of the lowerportion of the left front side frame 2 and a high-strength portion ofthe lower portion of the left crush can 4 correspond to each other.

In this way, when an impact load is applied to the left crush can 4 viathe bumper beam 6, the rear end portion of the left crush can 4 can befirmly and stably supported with the front end portion of the left frontside frame 2. Such a feature reduces the risk that the left crush can 4is displaced in an unexpected direction, so that the left crush can 4 iscrushed and deformed between the bumper beam 6 and the left front sideframe 2 to exhibit expected energy absorption performance. The same istrue to the right crush can 5.

Moreover, the upper horizontal rib 66 of the bumper beam 6 and the upperhorizontal rib 46 of the left crush can 4 are disposed at approximatelythe same height, and the lower horizontal rib 67 of the bumper beam 6and the lower horizontal rib 47 of the left crush can 4 are disposed atapproximately the same height. The ribs 66 and 67 and the ribs 46 and 47extend in the front and rear direction approximately coinciding with theinput direction of an impact load. Hence, the impact load is transmittedfrom the upper horizontal rib 66 and the lower horizontal rib 67 of thebumper beam 6 to the upper horizontal rib 46 and the lower horizontalrib 47 of the left crush can 4. In this way, at an initial stage inwhich the impact load at the time of a light collision is applied, theupper horizontal rib 46 and the lower horizontal rib 47 of the leftcrush can 4 are deformed such that the ribs 46 and 47 can be preventedfrom serving as props, so that the left crush can 4 is reliably crushedand deformed by the impact load at the time of the light collision.

Furthermore, when viewed from the vehicle front and rear direction, theupper wall part 41 of the left crush can 4 and the upper plate part 61of the bumper beam 6 are disposed at approximately the same height, andthe lower wall part 42 of the left crush can 4 and the lower plate part62 of the bumper beam 6 are disposed at approximately the same height.Hence, the impact load is transmitted from the upper plate part 61 andthe lower plate part 62 of the bumper beam 6 to the upper wall part 41and the lower wall part 42 of the left crush can 4. In this way, at theinitial stage in which the impact load at the time of the lightcollision is applied, the upper wall part 41 and the lower wall part 42of the left crush can 4 are deformed such that the upper wall part 41and the lower wall part 42 can be prevented from serving as props.

Furthermore, a part of the impact load is transmitted to the uppervertical rib 48 and the lower vertical rib 49 of the left crush can 4via the rear plate part 64 of the bumper beam 6. In such a case, whenviewed from the vehicle front and rear direction, the upper vertical rib48 and the lower vertical rib 49 of the left crush can 4 and the rearplate part 64 of the bumper beam 6 overlap each other, and thethicknesses of the upper vertical rib 48 and the lower vertical rib 49are thinner than that of the rear plate part 64 of the bumper beam 6.Hence, the upper vertical rib 48 and the lower vertical rib 49 can bedeformed with the rear plate part 64 of the bumper beam 6. Thus, theupper vertical rib 48 and the lower vertical rib 49 of the left crushcan 4 are prevented from serving as props.

When the left crush can 4 is crushed and deformed, since the inductionpart 40 is provided at the front portion of the right wall part 44 ofthe left crush can 4, the right front portion of the left crush can 4begins to be crushed and deformed and then the other portions begin tobe crushed and deformed. In this way, the right side and the left sideof the left crush can 4 can be crushed at the same timing, so that it ispossible to absorb energy by using the entire left crush can 4.

Furthermore, for example, when a collision load is applied to theintermediate portion of the bumper beam 6 in the vehicle widthdirection, the crushing deformation of the right wall part 44 of theleft crush can 4 is induced by the induction part 40, so that it ispossible to reduce the load transmitted to the inside of the left frontside frame 2 in the vehicle width direction via the right wall part 44.In this way, the deformation of the inside of the left front side frame2 in the vehicle width direction is reduced. The same is true to theright crush can 5.

As a consequence, the deformation of the left front side frame 2 and theright front side frame 3 at the time of a light collision is reduced.

Other Embodiments

The aforementioned embodiment is only a simple example in all respectsand it should be noted that it is not construed in a manner limited bythe example. Moreover, all modifications and changes belonging toequivalents of the claims are considered to fall within the scope of thepresent invention.

As in a modification example 1 illustrated in FIG. 12 to FIG. 15 and amodification example 2 illustrated in FIG. 16 to FIG. 19, a plurality ofcutout portions 70 to 73 and 80 to 83 may be provided at the right sideof the left crush can 4 by cutting off a part of a material. The cutoutportions 70 to 73 and 80 to 83 of the modification examples 1 and 2 areprovided at the front part of the left crush can 4 and operate similarto the aforementioned induction part 40.

The cutout portions 70 to 73 of the modification example 1 are locatedat portions separated from the front end portion of the right wall part44 to the rear side, are provided spaced apart from each other in thevertical direction, and serve as through holes. The upper and lower twocutout portions 70 and 73 are formed in the ridge line portions 4 a and4 c, respectively. The intermediate two cutout portions 71 and 72 areprovided continuously to the right end portions of the upper horizontalrib 46 and the lower horizontal rib 47, respectively.

Furthermore, the cutout portions 80 to 83 of the modification example 2are provided spaced apart from each other in the vertical direction, andare notches formed by cutting off a predetermined range from the frontend portion of the right wall part 44 to the rear side. The upper andlower two cutout portions 80 and 83 are formed in the ridge lineportions 4 a and 4 c, respectively. The intermediate two cutout portions81 and 82 are provided by continuous cutting to the right end portionsof the upper horizontal rib 46 and the lower horizontal rib 47,respectively.

In the modification examples 1 and 2, four cutout portions 70 to 73 andfour cutout portions 80 to 83 are provided; however, the presentdisclosure is not limited thereto and the number of cutout portions maybe 3 or less or 5 or more.

The aforementioned embodiment has described a case where the left frontside frame 2 and the right front side frame 3 are configured with apress-molded plate material; however, the present disclosure is notlimited thereto and the left front side frame 2 and the right front sideframe 3 may be configured with an extrusion molding member.

INDUSTRIAL APPLICABILITY

As described above, the impact absorption structure for the vehicleaccording to the present invention, for example, can be provided at thefront part of a passenger vehicle.

DESCRIPTION OF REFERENCE CHARACTERS

-   1 Impact absorption structure for Vehicle-   2, 3 Front Side Frame-   4, 5 Crush Can-   6 Bumper Beam-   41 Upper Wall Part-   42 Lower Wall Part-   43 Left Wall Part-   44 Right Wall Part-   46 Upper Horizontal Rib (First Rib)-   47 Lower Horizontal Rib (Second Rib)-   61 Upper Plate Part-   62 Lower Plate Part-   63 Front Plate Part-   64 Rear Plate Part-   66 Upper Horizontal Rib (First Rib)-   67 Lower Horizontal Rib (Second Rib)

The invention claimed is:
 1. An impact absorption structure for avehicle in which right and left crush cans are respectively attached tovehicle front end portions of front side frames disposed on both rightand left sides of the vehicle and extending in a vehicle front and reardirection, and a bumper beam is attached to vehicle front end portionsof the right and left crush cans to extend in a vehicle width direction,wherein each of the crush cans is formed in a cylindrical shapeextending in the vehicle front and rear direction and is providedtherein with a rib extending in the vehicle front and rear directioncontinuously to an inner surface of the crush can, the bumper beam isformed in a cylindrical shape extending in a vehicle width direction andis provided therein with a rib extending in the vehicle front and reardirection continuously to an inner surface of the bumper beam, the ribof the crush can and the rib of the bumper beam are disposed atapproximately a same height, the crush can includes an upper wall partand a lower wall part extending in the vehicle front and rear direction,the bumper beam includes an upper plate part and a lower plate partextending in the vehicle front and rear direction, and the upper wallpart of the crush can and the upper plate part of the bumper beam aredisposed at approximately a same height, and the lower wall part of thecrush can and the lower plate part of the bumper beam are disposed atapproximately a same height.
 2. The impact absorption structure for thevehicle of claim 1, wherein the crush can is provided therein with afirst rib and a second rib extending in the vehicle front and reardirection and spaced apart from each other in a vertical direction, thebumper beam is provided therein with a first rib and a second ribextending in the vehicle front and rear direction and spaced apart fromeach other in the vertical direction, and the first rib of the crush canand the first rib of the bumper beam are disposed at approximately asame height, and the second rib of the crush can and the second rib ofthe bumper beam are disposed at approximately a same height.
 3. Animpact absorption structure for a vehicle in which right and left crushcans are respectively attached to vehicle front end portions of frontside frames disposed on both right and left sides of the vehicle andextending in a vehicle front and rear direction, and a bumper beam isattached to vehicle front end portions of the right and left crush cansto extend in a vehicle width direction, wherein each of the crush cansis formed in a cylindrical shape extending in the vehicle front and reardirection and is provided therein with a rib extending in the vehiclefront and rear direction continuously to an inner surface of the crushcan, the bumper beam is formed in a cylindrical shape extending in avehicle width direction and is provided therein with a rib extending inthe vehicle front and rear direction continuously to an inner surface ofthe bumper beam, the rib of the crush can and the rib of the bumper beamare disposed at approximately a same height, wherein the rib of thecrush can is a horizontal rib extending in the vehicle width direction,the crush can is provided therein with a vertical rib extending from thehorizontal rib to the upper wall part or the lower wall part of thecrush can and extending in the vehicle front and rear direction, thebumper beam includes a rear plate part located at a vehicle rear side,when viewed from the vehicle front and rear direction, the vertical ribof the crush can and the rear plate part of the bumper beam are disposedto overlap each other, and a thickness of the vertical rib of the crushcan is set thinner than a thickness of the rear plate part of the bumperbeam.
 4. An impact absorption structure for a vehicle in which right andleft crush cans are respectively attached to vehicle front end portionsof front side frames disposed on both right and left sides of thevehicle and extending in a vehicle front and rear direction, and abumper beam is attached to vehicle front end portions of the right andleft crush cans to extend in a vehicle width direction, wherein each ofthe crush cans is formed in a cylindrical shape extending in the vehiclefront and rear direction and is provided therein with a rib extending inthe vehicle front and rear direction continuously to an inner surface ofthe crush can, the bumper beam is formed in a cylindrical shapeextending in a vehicle width direction and is provided therein with arib extending in the vehicle front and rear direction continuously to aninner surface of the bumper beam, the rib of the crush can and the ribof the bumper beam are disposed at approximately a same height, thecrush can is provided therein with a first rib and a second ribextending in the vehicle front and rear direction and spaced apart fromeach other in a vertical direction, the bumper beam is provided thereinwith a first rib and a second rib extending in the vehicle front andrear direction and spaced apart from each other in the verticaldirection, and the first rib of the crush can and the first rib of thebumper beam are disposed at approximately a same height, and the secondrib of the crush can and the second rib of the bumper beam are disposedat approximately a same height.